Crux Decussata was an X-shaped cross, also called St. Andrew's cross. The Crux Decussata was named after the Roman "decussis," or Roman numeral ten. It is believed that the Apostle Andrew was crucified on an X-shaped cross at his own request.

This “X” shaped cross (also known as “St. Andrew’s Cross”) borrowed its name from the Roman numeral ten (“decussis”). Two wooden planks were fastened together in an X configuration and the victim’s were nailed to the cross with arms outstretched on top ends of the X. Their feet were either nailed or tied separately to the bottom ends of the X.

Not only is the x-shaped cross, also called Saint Andrew’s cross, used to identify Saint Andrew in art, but it has been adopted as a heraldic device and features on the flags or arms of many countries and places that claim Saint Andrew’s patronage.